"use server"

import db from "@/db/db"
import { and, eq, inArray } from "drizzle-orm"
import { complianceResponses, redFlagManagers } from "@/db/schema/compliance"
import { basicContract, basicContractTemplates } from "@/db/schema/basicContractDocumnet"
import { vendors } from "@/db/schema/vendors"
import { users } from "@/db/schema"
import { getTriggeredRedFlagQuestions, type TriggeredRedFlagInfo } from "./red-flag-notifier"
import { getServerSession } from "next-auth"
import { authOptions } from "@/app/api/auth/[...nextauth]/route"
import { ApprovalSubmissionSaga } from "@/lib/approval"
import { htmlListConverter, htmlTableConverter } from "@/lib/approval/template-utils"
import type { ApprovalResult } from "@/lib/approval/types"
import { revalidatePath } from "next/cache"

type ContractSummary = {
  contractId: number
  vendorName: string | null
  vendorCode: string | null
  templateName: string | null
  createdAt: Date | null
  triggeredFlags: TriggeredRedFlagInfo[]
}

/**
 * RED FLAG 해소요청 - Approval Saga를 통해 상신
 */
export async function requestRedFlagResolution(contractIds: number[]): Promise<ApprovalResult> {
  if (!contractIds || contractIds.length === 0) {
    throw new Error("RED FLAG 해소요청을 위한 계약서를 선택해주세요.")
  }

  const uniqueContractIds = Array.from(new Set(contractIds))

  const session = await getServerSession(authOptions)
  if (!session?.user) {
    throw new Error("인증이 필요합니다.")
  }

  const currentUser = session.user
  if (!currentUser.epId) {
    throw new Error("Knox EP ID가 필요합니다.")
  }

  const currentUserId = Number(currentUser.id)
  if (Number.isNaN(currentUserId)) {
    throw new Error("유효한 사용자 정보가 필요합니다.")
  }

  const purchasingManagerEpId = await getPurchasingManagerEpId()
  if (!purchasingManagerEpId) {
    throw new Error("구매기획 담당자의 EP ID가 설정되지 않았습니다.")
  }

  const contractSummaries = await fetchContractsWithFlags(uniqueContractIds)
  if (contractSummaries.length === 0) {
    throw new Error("선택한 계약서에 RED FLAG가 존재하지 않습니다.")
  }

  const validContractIds = contractSummaries.map((contract) => contract.contractId)

  // 중복 해소요청 방지 (진행 중인 결재가 있는지 확인)
  const responses = await db
    .select({
      basicContractId: complianceResponses.basicContractId,
      redFlagResolvedAt: complianceResponses.redFlagResolvedAt,
      redFlagResolutionApprovalId: complianceResponses.redFlagResolutionApprovalId,
    })
    .from(complianceResponses)
    .where(inArray(complianceResponses.basicContractId, validContractIds))

  const missingResponses = validContractIds.filter(
    (contractId) => !responses.some((response) => response.basicContractId === contractId)
  )

  if (missingResponses.length > 0) {
    throw new Error("준법 응답 정보를 찾을 수 없는 계약서가 포함되어 있습니다.")
  }

  const blockedContracts = responses
    .filter((response) => response.redFlagResolutionApprovalId && !response.redFlagResolvedAt)
    .map((response) => response.basicContractId)

  if (blockedContracts.length > 0) {
    const blockedSummaries = contractSummaries
      .filter((contract) => blockedContracts.includes(contract.contractId))
      .map((contract) => contract.vendorName ?? `계약 ${contract.contractId}`)

    const preview =
      blockedSummaries.length > 2
        ? `${blockedSummaries.slice(0, 2).join(", ")} 외 ${blockedSummaries.length - 2}건`
        : blockedSummaries.join(", ")

    throw new Error(`이미 해소요청이 진행 중인 계약서가 있습니다: ${preview}`)
  }

  const now = new Date()
  const variables = await buildTemplateVariables(contractSummaries, {
    requesterName: currentUser.name || currentUser.email || "요청자",
    requestedAt: now,
  })

  const title = buildApprovalTitle(contractSummaries)

  const saga = new ApprovalSubmissionSaga(
    "compliance_red_flag_resolution",
    {
      contractIds: validContractIds,
      requestedBy: currentUserId,
      requestedAt: now.toISOString(),
    },
    {
      title,
      description: "컴플라이언스 Red Flag 해소요청",
      templateName: "컴플라이언스 Red Flag 해소요청",
      variables,
      approvers: [purchasingManagerEpId],
      currentUser: {
        id: currentUserId,
        epId: currentUser.epId,
        email: currentUser.email ?? undefined,
      },
    }
  )

  const result = await saga.execute()

  if (result.status === "pending_approval") {
    await db
      .update(complianceResponses)
      .set({
        redFlagResolutionApprovalId: result.approvalId,
        redFlagResolvedAt: null,
        updatedAt: new Date(),
      })
      .where(inArray(complianceResponses.basicContractId, validContractIds))

    await revalidatePath("/evcp/basic-contract")
    await revalidatePath("/evcp/compliance")
  }

  return result
}

/**
 * RED FLAG 해소 처리 (승인 후 실행)
 */
export async function resolveRedFlag(
  contractId: number,
  options: { approvalId?: string; revalidate?: boolean } = {}
): Promise<{ success: boolean; message: string }> {
  const conditions = [eq(complianceResponses.basicContractId, contractId)]
  if (options.approvalId) {
    conditions.push(eq(complianceResponses.redFlagResolutionApprovalId, options.approvalId))
  }

  const [updated] = await db
    .update(complianceResponses)
    .set({
      redFlagResolvedAt: new Date(),
      updatedAt: new Date(),
    })
    .where(and(...conditions))
    .returning({ id: complianceResponses.id })

  if (!updated) {
    throw new Error("해소요청 정보를 찾을 수 없습니다.")
  }

  if (options.revalidate !== false) {
    await revalidatePath("/evcp/basic-contract")
    await revalidatePath("/evcp/compliance")
  }

  return {
    success: true,
    message: "RED FLAG가 해제되었습니다.",
  }
}

async function getPurchasingManagerEpId(): Promise<string | null> {
  const [manager] = await db
    .select({
      purchasingManagerId: redFlagManagers.purchasingManagerId,
    })
    .from(redFlagManagers)
    .orderBy(redFlagManagers.createdAt)
    .limit(1)

  if (!manager?.purchasingManagerId) {
    return null
  }

  const [user] = await db
    .select({
      epId: users.epId,
    })
    .from(users)
    .where(eq(users.id, manager.purchasingManagerId))
    .limit(1)

  return user?.epId ?? null
}

async function fetchContractsWithFlags(contractIds: number[]): Promise<ContractSummary[]> {
  const contracts = await db
    .select({
      contractId: basicContract.id,
      vendorName: vendors.vendorName,
      vendorCode: vendors.vendorCode,
      templateName: basicContractTemplates.templateName,
      createdAt: basicContract.createdAt,
    })
    .from(basicContract)
    .leftJoin(vendors, eq(basicContract.vendorId, vendors.id))
    .leftJoin(basicContractTemplates, eq(basicContract.templateId, basicContractTemplates.id))
    .where(inArray(basicContract.id, contractIds))

  const withFlags = await Promise.all(
    contracts.map(async (contract) => {
      const triggeredFlags = await getTriggeredRedFlagQuestions(contract.contractId)
      return {
        ...contract,
        triggeredFlags,
      }
    })
  )

  return withFlags.filter((contract) => contract.triggeredFlags.length > 0)
}

async function buildTemplateVariables(
  contracts: ContractSummary[],
  meta: { requesterName: string; requestedAt: Date }
): Promise<Record<string, string>> {
  const summaryRows = contracts.map((contract) => ({
    contractId: contract.contractId,
    vendorName: contract.vendorName ?? "-",
    templateName: contract.templateName ?? "-",
    redFlagCount: contract.triggeredFlags.length,
  }))

  const summaryTable = await htmlTableConverter(summaryRows, [
    { key: "contractId", label: "계약 ID" },
    { key: "vendorName", label: "업체명" },
    { key: "templateName", label: "템플릿" },
    { key: "redFlagCount", label: "RED FLAG 수" },
  ])

  const detailSections = await Promise.all(
    contracts.map(async (contract) => {
      const questionList = contract.triggeredFlags.map((flag, index) => {
        const prefix = flag.questionNumber || `${index + 1}`
        return `${prefix}. ${flag.questionText}`
      })

      const listHtml = await htmlListConverter(questionList)
      return `
        <div style="margin-bottom: 24px;">
          <div style="font-weight:600;margin-bottom:8px;">
            계약 ID: ${contract.contractId} / ${contract.vendorName ?? "-"}
          </div>
          <div>${listHtml}</div>
        </div>
      `
    })
  )

  const detailHtml = detailSections.join("")
  const formattedDate = new Intl.DateTimeFormat("ko-KR", {
    dateStyle: "medium",
    timeStyle: "short",
  }).format(meta.requestedAt)

  return {
    요청자이름: meta.requesterName,
    요청일시: formattedDate,
    요청사유: "컴플라이언스 Red Flag 해소를 위해 구매기획 합의를 요청드립니다.",
    RedFlag요약테이블: summaryTable,
    RedFlag상세내역: detailHtml,
  }
}

function buildApprovalTitle(contracts: ContractSummary[]) {
  if (contracts.length === 0) return "컴플라이언스 Red Flag 해소요청"
  const firstVendor = contracts[0].vendorName ?? `계약 ${contracts[0].contractId}`

  if (contracts.length === 1) {
    return `Red Flag 해소요청 - ${firstVendor}`
  }

  return `Red Flag 해소요청 - ${firstVendor} 외 ${contracts.length - 1}건`
}